The genetics of cannabis lifetime use

Cannabis, which is increasingly legally available, both for therapeutic and recreational use, is now one of the most commonly used drugs worldwide. Of people who have ever used cannabis, studies vary, but they estimate that about 10-25 percent of people who use cannabis go on to develop cannabis use disorder.Uri Bright is a postdoctoral associate at the Yale School of Medicine and is one of the authors of a recent study in the journal Neuropsychopharmacology on the genetics of cannabis lifetime use — which is anyone who has ever used cannabis even once. That’s a distinct population from people who have cannabis use disorder, as his colleagues had looked into in the previous study. Hosted on Acast. See acast.com/privacy for more information.

Worry seems like something most people do from time to time, but for some people, severe worry can become an overwhelming sensation, and for older adults later in life, severe worry has been associated with an increased risk of stroke and coronary heart disease. Carmen Andreescu is a professor of psychiatry and bioengineering at the University of Pittsburgh School of Medicine. She says mild worry is useful evolutionarily, to help us make plans or adapt behavior.Read the full study here: https://www.nature.com/articles/s41386-025-02193-1 Hosted on Acast. See acast.com/privacy for more information.

There’s been a fair amount of animal data suggesting that nicotine can affect the developing brain, but there hadn’t been the equivalent human studies done on people whose brains are still developing. And today there are two predominant forms of nicotine delivery - tobacco cigarettes, and e-cigarettes, or vaping.Laurie Zawertailo is a senior scientist at the Center for Addiction and Mental Health in Toronto and an associate professor in the department of pharmacology and toxicology at the University of Toronto. Kanwar Boparai recently completed her PhD, working with Dr. Zawertailo, and is now a postdoc. For their new study, they and some colleagues recruited young adults age 18-25, and these people fell into three groups: one that had only smoked cigarettes, one that had only ever vaped, and a third that functioned as a control, that had never used either. They ended up with 26 smokers, 27 vapers, and 25 controls. This is the first human study to separate cigarette smokers and vapers into distinct groups.Read the full study here: https://www.nature.com/articles/s41386-025-02086-3 Hosted on Acast. See acast.com/privacy for more information.

Attention deficit hyperactivity disorder, or ADHD, is a common condition that, for a lot of people, is difficult to treat. The drugs that exist have a number of adverse side effects, and about 25 percent of patients don’t respond to existing drugs. And so a team of researchers in Iceland, led by Karl Karlsson, professor of biomolecular engineering at Reykjavik University, undertook a number of different steps to narrow in on and then test what the team has determined to be a novel treatment for ADHD, using an existing drug, amlodipine. Read the full study here: https://www.nature.com/articles/s41386-025-02062-x Hosted on Acast. See acast.com/privacy for more information.

Draulio Araujo, professor at the Brain Institute in the University of Rio Grande Norte in Natal, Brazil, has been studying ayahuasca for more than 20 years. It’s a psychedelic plant used in rituals in South America that has also been researched for its potential to treat depression. The effects of ayahuasca can last for hours and also lead to side effects including vomiting and diarrhea. The active psychedelic drug in ayahuasca is DMT, and so Dr. Araujo and his colleagues decided to conduct the first test of DMT itself, which is also an endogenous chemical and has been demonstrated to be safe.Read the full article here: https://www.nature.com/articles/s41386-025-02091-6 Hosted on Acast. See acast.com/privacy for more information.

New drugs that target the endocannabinoid system are being proposed for disorders that are usually characterized by the dysregulation of social processing, like social anxiety disorder and autism spectrum disorder. Researchers have been trying to understand the mechanisms for how these drugs work. Leah Mayo is assistant professor at the University of Calgary, and she’s one of the authors of a new study in the journal Neuropsychopharmacology in which they examined two aspects of the system. One is the endocannabinoid system itself. And then there’s another aspect of social processing called the C tactile system. Read the full study here: Endocannabinoid contributions to the perception of socially relevant, affective touch in humans | Neuropsychopharmacology Hosted on Acast. See acast.com/privacy for more information.

The scientific literature has shown that females demonstrate more aversion to risk-taking than males. Studies have also demonstrated that the basal lateral amygdala, or BLA, is a critical hub for processing risk and reward information. And yet further research has shown that activity in the amygdala differs between males and females, and that the expression of particular dopamine receptors called D2 receptors are greater in females than in males. The authors hypothesized that one mediating mechanism that leads to greater risk aversion in females is differential activity of dopamine in the basal lateral amygdala. Caitlin Orsini is an assistant professor in the departments of psychology and neurology at UT Austin.  Hosted on Acast. See acast.com/privacy for more information.

The menstrual cycle is known to affect things like mood and changes in pain. But there can also be symptoms that have a serious impact on a person’s function, ability to work, ability to maintain friendships and romantic relationships. This is a rare condition known as premenstrual dysphoric disorder. But it’s not the only psychiatric condition that can worsen with changes in the menstrual cycle. For instance, nearly 60 percent of menstruating patients with depression can experience cyclical worsening similar to PMDD. Conditions such as these are generally referred to as menstrual cycle affective change. Menstrual cycle affective change is more common in those with chronic psychiatric disorders.  The authors are interested in reframing the conversation around menstrual cycle affective change to be something that is a more fundamental process that we can study across disorders, across categories, and identify biomarkers that might help us predict who's going to have those symptoms in more complex ways than we might be able to do with categories. This paper represents how can we take this dimensional way of thinking about menstrual cycle affective change and talk about the specific ways that we can be precise in looking at the time the time characteristics of that, the specific mechanisms, et cetera. Tory Eisenlohr-Moul is an associate professor of psychiatry at the University of Illinois at Chicago in the department of psychiatry, and she’s one of the authors. Jordan Barone is an MD/PhD candidate at the University of Illinois at Chicago, and she’s another author.  Hosted on Acast. See acast.com/privacy for more information.

Researchers are interested in understanding the biology of why some people are more likely to overconsume substances. Some substances are difficult to study—people might not admit to illegal substance abuse or to how much alcohol they drink. But Americans are more likely to accurately recall and share how much coffee they drink—which is related to how much caffeine they consume. And so a team of researchers paired up with the company 23 and Me to try to understand genetic differences among a large set of people, to try to tease out any genetic similarities that could be correlated with coffee consumption. Sandra Sanchez-Roige is an associate professor in the department of psychiatry at the University of California San Diego, and she’s one of the study’s authors. Abraham Palmer is a professor and vice chair of basic research in the department of psychiatry at UC San Diego, and he’s another of the study’s authors. Read their full study here: https://www.nature.com/articles/s41386-024-01870-x Hosted on Acast. See acast.com/privacy for more information.

Scientists have been amassing an increasing amount of evidence about the impact of racial discrimination and racial trauma, including how it can have an impact on brain regions involved with threat vigilance and emotional regulation. At the same time, there’s evidence that increased engagement in those areas has been linked to increased risk of mental health problems like depression, and they also suspect it could be a vulnerability for brain health issues such as dementia and Alzheimer’s disease. Negar Fani is an associate professor in the department of psychiatry and behavioral sciences at Emory University School of Medicine, and she worked with Aziz Elbasheir, a PhD candidate at Emory University in the neuroscience program, on the study. They knew that C-reactive proteins, or CRPs, are a marker of immune activation in the blood.Read their full study here: https://www.nature.com/articles/s41386-023-01737-7 Hosted on Acast. See acast.com/privacy for more information.